Comparison of the Performance of CoP-Coated and Pt-Coated Radial Junction n⁺p-Silicon Microwire-Array Photocathodes for the Sunlight-Driven Reduction of Water to H₂(g)
Abstract
The electrocatalytic performance for hydrogen evolution has been evaluated for radial-junction n^+p-Si microwire (MW) arrays with Pt or cobalt phosphide, CoP, nanoparticulate catalysts in contact with 0.50 M H_2SO_4(aq). The CoP-coated (2.0 mg cm^(–2)) n^+p-Si MW photocathodes were stable for over 12 h of continuous operation and produced an open-circuit photovoltage (V_(oc)) of 0.48 V, a light-limited photocurrent density (J_(ph)) of 17 mA cm^(–2), a fill factor (ff) of 0.24, and an ideal regenerative cell efficiency (η_(IRC)) of 1.9% under simulated 1 Sun illumination. Pt-coated (0.5 mg cm^(–2)) n^+p-Si MW-array photocathodes produced V_(oc) = 0.44 V, J_(ph) = 14 mA cm^(–2), ff = 0.46, and η = 2.9% under identical conditions. Thus, the MW geometry allows the fabrication of photocathodes entirely comprised of earth-abundant materials that exhibit performance comparable to that of devices that contain Pt.
Additional Information
© 2015 American Chemical Society. Received: March 9, 2015; Accepted: April 7, 2015; Publication Date (Web): April 20, 2015. This work was supported by the NSF CCI Solar Fuels Program (CHE-1305124) and the Center for Individual Nanoparticle Functionality (CINF) (DNRF54). C.W.R. thanks the National Science Foundation and Link Energy Foundation for graduate research fellowships. Research was in part carried out at the Molecular Materials Research Center of the Beckman Institute of the California Institute of Technology. N.S.L. acknowledges support from the Energy from Sunlight Project funded by the Gordon and Betty Moore Foundation (GBMF1225).Attached Files
Supplemental Material - jz5b00495_si_001.pdf
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Additional details
- Alternative title
- Comparison of the Performance of CoP-Coated and Pt-Coated Radial Junction n^+p-Silicon Microwire-Array Photocathodes for the Sunlight-Driven Reduction of Water to H_2(g)
- Eprint ID
- 57042
- DOI
- 10.1021/acs.jpclett.5b00495
- Resolver ID
- CaltechAUTHORS:20150428-095042468
- NSF
- CHE-1305124
- Danish National Research Foundation
- DNRF54
- Link Energy Foundation
- Gordon and Betty Moore Foundation
- GBMF1225
- Created
-
2015-04-28Created from EPrint's datestamp field
- Updated
-
2023-09-27Created from EPrint's last_modified field
- Caltech groups
- CCI Solar Fuels